A number of sophisticated electronic lock systems have been developed over the past several years. In such systems the user inserts a key, often in the nature of a plastic card having an identifying code magnetically or optically stored thereon, into a slot. The code is read and if the code is correct powered electrical/electronic apparatus will perform such functions as raising a bar to allow a car to drive into a garage, asking the cardholder to enter data onto a keyboard or a touch pad as in automatic teller machines, allowing the user to turn a handle to enter a hotel room, etc.
Each of the above discussed prior art systems requires an external power source to run the electronics, lift the bar, draw the bolt, etc. As a result, a good deal of the cost of such systems is in wiring the mechanism to be operated and the electrical/electronic apparatus for receipt of electrical power. This is perhaps not a great problem when the power is being used to control entry to a garage. On the other hand, when it is being used for the purpose of controlling entry to a hotel room, each door of the hotel must be wired to receive power or must contain a battery power service. This is a quite expensive operation and has greatly limited the use of such sophisticated electronic locking systems.
Also, there are some instances where it is simply inconvenient to carry a portable power supply, even a battery. For example, if one is fishing in a mountain stream it is desirable to be able to adjust the tension in the line in order to properly play a fish. Present day nonelectronically controlled reels provide this capability utilizing a ratchet type of system. However, the effective amount of resistance to the fish's struggles varies dependent on how much of the line is paid out since the effective diameter, from the center of the reel to the point at which the line leaves the reel, varies. A system which would instantaneously measure the amount of pull being exerted by a fish and which would adjust the tension accordingly would be desirable. Providing such a currently non-existant system, using present day technology, would require the installation of a battery and proper connections within the reel.
Some attempts have been made to utilize in-the-door power generation to eliminate the need for an external power source. German Offenlegungsschrift No. 2,324,392, PCT International Publication Number WO 80/02710 and U.S. Pat. No. 4,433,355 all show the use of in-the-door electrical generators to power electronic decision makers and to move bolts or gates which allow latches to be moved. All of such apparatus, however, utilize magnetic fields (e.g., solenoids) which require that an electric current be sustained in their coils whereby power is continuously consumed. Thus, such apparatus requires the generation of considerable power. And, to generate such power various gearing must be provided along with springs, etc. Furthermore, the generation of such power requires considerable movement, such as cranking and can generate considerable noise as gears move against one another, springs are loaded and their energy discharged to power a generator, the generator spins, etc. To date such problems have precluded the successful entry of any such apparatus into commercial acceptance.